The following method has been previously known as a method for quickly performing determination of a reading position in an AV stream and decoding processing and quickly retrieving a specified mark in reproducing a recording medium on which a plurality of pieces of data including video data, audio data, and the like are recorded (see Japanese Patent Laid-Open No. 2002-158971, for example).
According to the method, a stream of an entity of contents is managed by Clip Information and reproduction of the AV stream is managed by a PlayList. As attribute information of the AV stream, address information RSPN_arrival_time_discontinuity on discontinuity points in the AV stream, information EP_map or TU_map for associating time information with address information in the AV stream, and time information ClipMark on a characteristic image in the AV stream are recorded in the Clip Information.
There is DVD (Digital Versatile Disc) video, in particular, as the above-mentioned recording medium on which a plurality of pieces of data including video data, audio data, and the like are recorded. A format of the DVD video defines multiangle reproduction. In a predetermined reproducing section allowing multiangle reproduction, a user can select an angle that suits preference of the user. At this time, change between angles can be performed seamlessly by a recording and reproducing apparatus.
FIG. 1 is a diagram of assistance in explaining a multiangle format of a DVD video.
A multiangle reproducing section includes a plurality of reproducing sections. One of the reproducing sections is referred to as a Cell. In the example of FIG. 1, the multiangle reproducing section includes Cell#i+1 to Cell#i+3 of three angles, that is, an angle 1 (Angle#1) to an angle 3 (Angle#3). AV stream data of an entity corresponding to Cells is referred to as a VOB (Video Object). A VOB corresponding to each Cell for forming a multiangle is divided into units referred to as ILVUs (Interleaved Units) not shown in the figure. The plurality of VOBs including the multiangle are multiplexed in ILVU units. Incidentally, each ILVU starts with a Closed GOP (Group of Pictures).
Description will be made of seamless angle change reproduction in a multiangle of a DVD video. When a user changes a reproduction path from the angle 2 to the angle 1 and then to the angle 3, for example, the recording and reproducing apparatus sequentially reads and reproduces data of an ILVU 1, an ILVU 2, and an ILVU 3 (none of them are shown) while jumping on the disk. Incidentally, each ILVU starts with DSI (Data Search Information), and the DSI has an address of a next ILVU of each angle to which to jump.
However, since DSI is embedded in an AV stream referred to as VOB, it is difficult to obtain information on an address where each piece of angle data to be reproduced next is stored, unless the AV stream is read. Hence, it takes time to read in advance all information on addresses where pieces of angle data to be reproduced in the future are stored, because all AV streams need to be read.